Use pigz for increased backup and restore performance on multicore machines if available

What does this MR do?

This MR enables the usage of pigz for creating and restoring backups if it is available on the machine. On my PC this allowed ~70% faster packaging compared to gzip.

Are there points in the code the reviewer needs to double check?

everything. It's a small change, but non working backup and restore would be bad.

Why was this MR needed?

Currently the backup and restore task uses gzip which only runs on a single core, so it's pretty slow. pigz is "A parallel implementation of gzip for modern multi-processor, multi-core machines" Information on pigz: http://www.zlib.net/pigz/

What are the relevant issue numbers?

closes #20773 (closed)

Screenshots (if relevant)

Does this MR meet the acceptance criteria?

• CHANGELOG entry added
• Documentation created/updated
  - [ ] API support added
• Tests
  - [ ] Added for this feature/bug
• All builds are passing
• Conform by the style guides
• Branch has no merge conflicts with master (if you do - rebase it please)
• Squashed related commits together